From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D742C433E3 for ; Wed, 12 Aug 2020 10:37:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3C3F20838 for ; Wed, 12 Aug 2020 10:37:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="KA3A4rKf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726983AbgHLKhR (ORCPT ); Wed, 12 Aug 2020 06:37:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726404AbgHLKhR (ORCPT ); Wed, 12 Aug 2020 06:37:17 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDFDCC06174A; Wed, 12 Aug 2020 03:37:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=a6/dAk8hzb0WYY+kQF71Fgx1O3nwOedWBapk4f0aaOE=; b=KA3A4rKfqtBkAolbpGhZQn0gae rIqsIfEejxM64L+YMTBJUSvg9fEFIfvHxwctOuhc9kOyfSdozptYsA0jAOiKaRSfUdNi72MKP9/pK nkS/znp2LKbSteLjA3WozUbWSHli0WpEytH2VWZvz/eAOBqRX+XYtpWzwnEOCloZYCLFOC3afCNHm rkq0HuJB3Rc7Zw8PRD3F29LxE2f6cEgqiZbZbThXq4+UEfKq9D08M/+swMXJRha+LvkLztxW2QGL2 ViWxhZVhOuYLHsAyeFHBmHL/uIcJ0MWeVdzlotQr4696vPqatWO8tc8k9EQnzrdgHJJkzsiPQxZg3 zd6QAwzg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5o6c-0008Cw-Cp; Wed, 12 Aug 2020 10:36:12 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 911FF300DAE; Wed, 12 Aug 2020 12:35:30 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 787BB2B412CB6; Wed, 12 Aug 2020 12:35:30 +0200 (CEST) Date: Wed, 12 Aug 2020 12:35:30 +0200 From: peterz@infradead.org To: Nicholas Piggin Cc: Alexey Kardashevskiy , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Ingo Molnar , Will Deacon Subject: Re: [PATCH 1/2] lockdep: improve current->(hard|soft)irqs_enabled synchronisation with actual irq state Message-ID: <20200812103530.GL2674@hirez.programming.kicks-ass.net> References: <20200723105615.1268126-1-npiggin@gmail.com> <20200807111126.GI2674@hirez.programming.kicks-ass.net> <1597220073.mbvcty6ghk.astroid@bobo.none> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1597220073.mbvcty6ghk.astroid@bobo.none> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 12, 2020 at 06:18:28PM +1000, Nicholas Piggin wrote: > Excerpts from peterz@infradead.org's message of August 7, 2020 9:11 pm: > > > > What's wrong with something like this? > > > > AFAICT there's no reason to actually try and add IRQ tracing here, it's > > just a hand full of instructions at the most. > > Because we may want to use that in other places as well, so it would > be nice to have tracing. > > Hmm... also, I thought NMI context was free to call local_irq_save/restore > anyway so the bug would still be there in those cases? NMI code has in_nmi() true, in which case the IRQ tracing is disabled (except for x86 which has CONFIG_TRACE_IRQFLAGS_NMI).